In electrical power distribution devices, circuit interrupters such as circuit breakers are used to protect power lines and other distribution devices from excessive current flows. The loads connected to these distribution devices must also be protected from voltage surges. Surge arresters suppress voltage surges to a less damaging level by presenting a decrease in impedance upon higher voltages. The resulting low impedance circuit effectively limits surge currents flowing through the distribution devices so that they are not damaged by the surges.
Surge arresters in the prior art have problems with overshooting the preselected voltage level before the overvoltage is suppressed. The voltage overshoot risks damage to the devices which the surge arrester is to protect. Some prior art surge arresters utilize poorly designed fusing methods which can create the potential of explosion or fire.
To complicate matters further, the space allocated to surge arrester circuitry in load centers and panelboards makes it difficult to package enhanced functionality accessories in the available space. Thus, the placement of the protective circuitry is a problem that must be overcome.